That white '75 70 series is the exact machine I bought with my mom. We got it for its "Quiet Pak" system, and it did live up to its name in that regard. Even quieter during agitation than its Maytag contemporaries. The Penta-Swirl agitator added to the quietness. Much as I wanted to get a Maytag, they were far too expensive with a stripped down model of much smaller capacity costing the same or more as the 70 series. For 25 years of service, Mom got her money's worth out of the Kenmore.
As for only three water levels on the pair you're getting, don't expect a whole lot of range from them. While my mom's machine had infinite water level, the lowest setting still filled the tub almost half way.
Beware of any spray stain removers. They'll also remove the paint from the dial face and (70 series) simulated wood panels.